For kicks, I went down the list of one of my most favorite systems to visit and checked.
I never looked before, its closeish (~1,400 Ly I think) to the bubble and I don't need to search for material often so I never checked, but I always visit this place.
Only Mercury, Yittrium and Polonium are rare, but there availible on at least one moon each. Tungsten two, and Selenium three. The rest have 4+ moons to dig through, all within 6k of the entry as I recall.
The sights are worth it. 5 stars within 100 ls of each other usually. Can't top that.
Outopps KI-B d13-13